ruby-dbus 0.3.1

I have made a bug-fix release of ruby-dbus, a Ruby language binding for the D-Bus IPC system.

• Many on_signal could cause DBus.Error.LimitsExceeded (bnc#617350).
  Don't add a match rule that already exists, enable removing match rules. Now only one handler for a rule is called (but it is possible for one signal to match more rules). This reverts the half-fix done to fix Issue#3.
• Re-added InterfaceElement#add_param for compatibility.
• Handle more ways which tell us that a bus connection has died.

RPMs can be found via Webpin.